I’ve mentioned a number of Xcode plugins including a couple for formatting your code to make it more readable.

Here’s an Xcode plugin called Polychromatic from Kolin Krewinkel that aims to make your code in Xcode more understandable by providing intelligent and customizable code coloring that provides each variable with a unique color.

As the readme states:

Polychromatic is an Xcode plugin that truly emphasizes content. By giving properties, ivars, and local variables each a unique, dynamic color, and stripping away color from types which do not need it, logic becomes clear and apparent.

You can customize the colors used, saturation, and brightness.

Here’s an example image from the readme showing the coloring with the default Polychromatic plugin colors: